Blood test system

ABSTRACT

A CAP ADAPTED TO HOLD A MICRO-PIPETTE IN SUBSTANTIALLY COAXIAL POSITION WITHIN A VIAL. THE CAP HAS AN OUTER CYLINDRICAL FLANGE WHICH RELEASABLY ENGAGES THE MOUTH OF THE VIAL, AND AN INNER CYLINDRICAL RESILIENT TUBULAR PLUG POSITIONED COAXIALLY WITHIN THE FLANGE. A FLAP WITH AN APERTURE IN ITS LOWER END EXTENDS FROM THE FREE END OF THE TUBULAR PLUG INTO THE VIAL. THE TUBULAR PLUG AND THE FLAP HOLD THE MICRO-PIPETTE. PROTUBERANCES EXTENDING FROM THE TOP OF THE CAP ARE USED TO ATTACHED A RECORD CARD.   D R A W I N G

Feb. 26, 1974 E. J. RAPOZA ETAL 3,794,469

BLOOD TEST SYSTEM Original Filed March 2, 1970 8 Sheets-Sheet 1 /0 [a Z/2 I N Q I; l W: F g 155 37 I 42 38 H f 29 n 1 v I Q L .2 a 4/ ll l I 057 65 I 30 I I I 55 l4 Feb. 26, 1974 E. J. RAPOZA ETAL BLOOD TEST SYSTEM8 Sheets-Sheet 2 Original Filed March 2, 1970 ounkm Feb. 26, 1974 E. J.RAPOZA ETAL 3,794,469

BLOOD TEST SYSTEM Original Filed March 2, 1970 8 Sheets-Sheet 5 PROFILEI \d/ /20 F F/G.Z4

Feb. 26, 1974 E. J. RAPOZA ET AL BLOOD TEST SYSTEM Original Filed March2', 1970 8 Sheets-Sheet 4 Or'iginal Filed March 2, 1970 Feb. 26, 1974 E.J. RAPOZA L 3,794,469

BLOOD TEST SYSTEM 8 Sheets-Sheet 5 FIG] Feb. 26, 1974 J, RAPOZA ETALBLOOD TEST SYSTEM 8 Sheets-Sheet 6 Original Filed March 3, 1970 P H ;:N64

HC T 7D 60 I0 lllllllllllllllllllllllLlllHlllll 1974 E. J. RAPozA ETAL3,794,469

BLOOD TEST SYSTEM Original Filed March 2, 1970 8 Sheets-Sheet 7 Feb. 26,1974 J RAPOZA EIAL BLOOD TEST SYSTEM 8 Sheets-Sheet 8 Original FiledMarch 2, 1970 United States Patent O Int. Cl. B011 3/00 US. Cl. 23-292 6Claims ABSTRACT OF THE DISCLOSURE A cap adapted to hold a micro-pipettein substantially coaxial position within a vial. The cap has an outercylindrical flange which releasably engages the mouth of the vial, andan inner cylindrical resilient tubular plug positioned coaxially withinthe flange. A flap with an aperture in its lower end extends from thefree end of the tubular plug into the vial. The tubular plug and theflap hold the micro-pipette. Protuberances extending from the top of thecap are used to attach a record card.

This is a division of application Ser. No. 15,469, filed Mar. '2, 1970,now US. Pat. 3,706,499, issued Dec. 19, 1972.

BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates toa system for performing colorimetric analysis of fluid samples. Moreparticularly, the invention relates to a colorimetric system useful indetermining the components of a blood sample for diagnostic purposes.

It is well known that quantities of important blood components may bedetermined by measuring the light transmitted through a properly reactedsample. For each determination, the blood sample is reacted into acomplex that will show, by its light transmission characteristics, theconcentration of the component of interest. Typical of the tests whichmay be conducted in this manner are determinations for hemoglobin,glucose, cholesterol, urea nitrogen, uric acid, and bilirubin.

Colorimeters of known design comprise as essential elements a lamp, asample holding well, a photocell, a meter for indicating the output ofthe photocell, and the associated circuitry. The intensity of the lightpassing through the sample is monitored by the photocell, which in turncontrols the readout of the meter. Since the optical density of thesample varies with the wave length of the light passing through thesample, it is conventional practice to position a filter in front of thephotocell such that the wave length which is most sensitive to changesin the optical density of the sample is being monitored.

In the instrument of the present invention, a removable plug-in moduleshares some of the above functions with the instrument itself. Inparticular, the meter scale for the readout meter needle is positionedon the module, and part of the meter circuitry is in the module. By thisarrangement, both the scale reading and circuitry of a particular modulemay be used to calibrate the instrument to the requirements of aspecific blood determination. By employing a number of modules, eachdesigned to calibrate the instrument for a different blood test, theinstrument may be used to quickly and accurately perform any number ofdifferent tests. The circuitry in the module includes an adjustable zeroset for the meter, and a calibration adjustment for correcting thecalibration of ice the instrument for inherent variations in thechemistry of the reagents employed. Removing a module from theinstrument and replacing it will not upset its calibration.

The instrument of this invention further includes a rotary turntable orcarousel for conveniently retaining a number of modules in theinstrument. When the carousel is turned to swing a module into itsoperative or meter position, that modules scale (which may becolor-coded to the particular test being conducted) aligns itself infront of the instruments indicating meter. The scale is graduated andnumbered for the one specific determination associated with that module,and it reads directly in appropriate units.

In order to provide a permanent record of the determination results, apaper like patient record card may be removably attached to the uppersurface of the module. The card, which may be color-coded along with itsassociated module to indicate a particular determination, includes aprinted scale corresponding to the scale of the module. The test resultsmay thus be marked directly on the card which, when removed, serves as apermanent record.

Since the particular test or determination being conducted will oftenrequire that a specific filter be positioned in the light path of thelamp, a mechanism is provided to automatically position the properfilter when the module is rotated in the carousel to its meter position.This mechanism takes the form of a cam pin positioned on the modulewhich is adapted to engage a lever arm. A number of filters are mountedat the opposite end of the lever arm, and movement thereof swings theproper filter into position. Each module has its pin positioned in apreselected location such that movement of the lever arm and thusselection of the filter will be automatically correlated to theparticular test being conducted.

The instrument of the present invention may further include twoincubator blocks together with temperature regulating controls tomaintain them at C. and 37 C., respectively, when the instrument isturned on. These incubator blocks are designed to hold the reactionvials or cuvettes while reaction is taking place. A third unheatedincubator block may also be provided for room temperature reactions.Since the reaction between the blood component of interest and thereagent for each test is generally permitted for a predetermined time,the instrument may also included a built-in timer.

The removable patient record card incorporates several novel featureswhich are significant aspects of the present invention. The cardinitially includes tear-off tabs which, together with the card itself,are adapted to be marked with an identifying patient number. These tabsare then attached to any vessel containing the patients blood sample,the micro-pipette utilized to transfer the sample in the proper amountand to the cap of the reagent cuvette. As noted above, each card may becolor-coded to indicate the particular test for which it is designed. Bythis arrangement, identification of each blood sample by patient andtest is assured.

The patient record card also yields a significant advantage in that itprovides a permanent visual record of the test results. In particular,the removable card permits organization of permanent patient records inmeaningful graphical displays which aid the physician in his diagnosis.Very often, trends and variations that show up over a period of timemean more than the value of any single blood component determination. Ifblood tests are made at regular inervals over a period of time, thecards resulting from each test may be arranged in overlying sequence ona suitable form provided for this purpose. In such arrangement, themarked scales create, virtually, a graph plotted against time with aprogression of determination marks which can be scanned at a glance.Thus it is very easy to spot consistencies, sharp variations, or gradualtrends. The monitoring form may further include a clear plastic overlayhaving indicia thereon which are adapted to overlie the marked scales toindicate the normal range of test results.

The use of patient record cards as described herein also permits theassembly of a single graphic display of all the blood chemistrydeterminations obtained at one time. Presenting all of this informationto the physician in a single graphic display may revealinterrelationships which indicate the patients general physicalcondition. The use of the removable patient record cards is well suitedfor this type display since they may be easily mounted in a suitablefolder.

A further aspect of the present invention resides in the structure ofthe cap for the reagent cuvette. The cap is designed to hold themicro-pipette containing the blood sample in the cuvette in such amanner that the contents of the micro-pipette may be thoroughly rinsedout and mixed with the reagent in the cuvette. In this regard, it isimportant that the cap hold the micro-pipette in the upper portion ofthe cuvette and out of the light path in the colorimeter so that thepresence of the micro-pipette will not effect the colorimetricdetermination. The cap further functions to provide a leak resistantinside-outside seal at the mouth of the cuvette. In addition, theoutside portion of the cap includes a number of protuberances which aredesigned to receive and retain the identifying tear-off tabs of thepatient record scale.

Among the more specific objects of the present invention are thefollowing:

1) The provision of a simple and fool-proof system for performing avariety of common blood component determinations.

(2) The provision of a blood testing system which is self-contained toprovide the user with all of the imple ments necessary to successfullycarry out any one of the conventional determinations.

(3) The provision of a photometer which includes a zero-set adjustmentfor the meter and which may be calibrated with a standard reagent.

(4) The provision of a removable module which incorporates theelectrical components for zero-set and calibration of the meter suchthat insertion of the module is all that is required to completelycalibrate the instrument.

(5) The provision of a read-out scale on the module which is correlatedto the calibration circuitry of the module such that, by the act ofselecting a test module, the proper scale will be positioned adjacentthe meter.

(6) The provision of a removable paper patient record card having aread-out scale, the scale being adapted to be positioned over thecorresponding scale of the module where it may be marked to indicate themeter reading. The scale then serves as a permanent record of the testresults.

(7) The provision of a number of optical filters for the instrumentwhich are individually selected and positioned in the photometer by themodule.

(8) The provision of a system for identifying blood samples by patientand test.

(9) The provision of a reagent cuvette cap which is able to retain amicro-pipette in coaxial relationship.

The above objects and advantages of the present invention are achievedin the embodiment more particularly described hereinafter. Additionalobjects and advantages will become apparent to those skilled in the artfrom the following detailed disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of theinstrument of the present invention illustrating the manner in which theremovable modules are assembled on the carousel of the instrument.

FIG. 2 is a schematic representation of the circuitry employed in thepresent invention.

FIG. 3 is an overhead plan view of the instrument, the top cover beingremoved.

FIG. 4 is a sectional side view taken along the line 4-4 in FIG. 1.

FIG. 5 is a fragmentary view of the instrument as shown in FIG. 3, andillustrating the manner in which the filter lever arm is rotated by themodule at the meter read-out position.

FIG. 6 is a fragmentary sectional view of the photometer taken along theline 6-6 of FIG. 5.

FIG. 7 is a fragmentary sectional view taken along the line 77 of FIG. 5and illustrating the manner in which the module cam pin engages thelever arm.

FIG. 8 is a fragmentary sectional view taken along the line 8-8 of FIG.5 and illustrating the manner in which the module is electricallyconnected to the instrument.

FIG. 9 is a top plan view of the removable module.

FIG. 10 is a rear elevational view of the module.

FIG. 11 is a sectional plan view of the module taken along the line11-11 of FIG. 10.

FIG. 12 is a sectional side view of the module taken along the line 1212of FIG. 11.

FIG. 13 is a diagram of the circuitry contained in the module.

FIG. 14 is a plan view of the patient record element.

FIG. 15 is a side view of the patient record element taken along theline 15-15 of FIG. 14.

FIG. 16 is a perspective view of the cuvette cap showing a retainedmicro-pipette and the manner in which the tearoff tab of the patientrecord element may be attached thereto.

FIG. 17 is a perspective view showing the manner in which the tear-01ftab may be attached to a micropipette.

FIG. 18 is a side view of the reagent cuvette, with the open end beingclosed by a cap holding a micro-pipette inside the cuvette.

FIG. 19 is a top plan view of the cuvette cap.

FIG. 20 is a sectional side view of the cuvette cap taken along the line2020 of FIG. 19.

FIG. 21 is a sectional side view taken along the line 2121 in FIG. 19and showing the micropipette retained thereon.

FIG. 22 is a bottom plan view of the cap.

FIG. 23 is a perspective view of the patient monitoring form and itsclear plastic overlay.

FIG. 24 is a plan view of the patient profile form.

DESCRIPTION OF THE PREFERRED EMBODIMENT The instrument of the presentinvention is illustrated generally at 10 in the drawings and includes anupper molded plastic cover 12 and a lower molded plastic base 14 whichenclose the various components of the device. Viewing FIG. 1, it will beobserved that the exterior of the instrument includes an off-on switch16, a test Well guide 18, a C. incubator block 20, a 37 C. incubatorblock 22, and a room temperature incubator block 23. Each of theseincubator blocks includes a number of openings 21 adapted to receive anoptically correct reagent vial or cuvette 25. A conventional mechanicaltimer 24 may be provided as a means for conveniently measuring thereaction times. Any similar timing means such as a conventionalelectrical timer, may also be effectively utilized. The upper cover 12of the instrument further includes an entry opening 26 for a removabletest module 27, and a meter read-out opening or station 28.

Removal of the upper cover 12 reveals the internal components of theinstrument as shown in FIG. 3. These components include as salientfeatures the read-out meter 29, the carousel 30, the photometer 32, andthe filter lever arm 34.

The carousel 30, which may be fabricated from any suitable plasticmaterial, generally comprises a circular disc rotatably supported abouta central bearing pin 35 (FIG.

4). The upper peripheral surface of the carousel includes t our spaceups an mg ugs e nlng u i rected module receiving stations therebetween.For the purposes hereinafter described, each module receiving stationincorporates a pair of module retaining clips 37, a radial slot 38through the body of the carousel, and an opening 39 to expose a numberof electrical contacts 40. To prevent inadvertent rotation of thecarriage, a ball detent arrangement is provided which includes a ball41- resiliently mounted in the frame member 42. The ball is adapted toenter a tapered entrance 43 at the end of each slot 38 as each modulereceiving station comes into alignment with the meter 29.

The meter 29 is a conventional milliammeter, and is supported by theframe member 42 to overlie the central portion of the carousel. Themeter includes a read-out needle 45 which is adapted to sweep across thelower module receiving (or read-out) station. It will be noted that themeter 29 does not include an attached printed scale.

The photometer 32 is illustrated in detail in FIGS. 5 and 6. Asessential elements, the photometer includes an electrical lamp 47, atest well 48, and a photocell 49. The well 48 includes a resilientspring arm 51 along one side which is adapted to press the cuvette 25into a predetermined fixed position against the V-shaped opposite wall50 when the cuvette is axially inserted. By this arrangement, thecuvette is accurately aligned in the light path between the lamp andphotocell. To further facilitate the accurate alignment of the cuvette,the test well guide 18 may be mounted so as to be laterally adjustableon the cover 12, note FIG. 6. As will be further explained, movement ofthe arm 51 by the entry of the cuvette causes a control arm 52 toactuate an electrical switch 53.

As noted above, it is often desirable that a filter be placed in thelight path of the photometer so that a specific wave length is beingmonitored. Since different tests will require different filters foroptimum results, the present invention contemplates a mechanism forautomatically positioning a filter in the light path, the particularfilter being chosen by the particular module at the read-out position onthe carousel. For this purpose, the lever arm 34, which is pivoted forrotation about the pin 55, includes an arcuate row of filters 56attached at one end. In the illustrated embodiment, the row is shown toinclude six filters but it will be appreciated that any number could bepositioned in the row. As shown in FIGS. 3, 5, and 6, movement of thelever arm causes the filters to sequentially pass into the light path ofthe photometer. The opposite end of the lever arm includes a circularwheel 57 which is adapted to be engaged by the module in a mannerhereinafter described. Also, a spring 58 acts to restrain the lever armin the position shown in .FIG. 3.

The removable test module 27 is illustrated in detail in FIGS. 9-12. Themodule is fabricated from a suitable plastic material and includes a topcover 60 and a base plate 61. The outer surface of the top coverincludes a printed scale 62 positioned along an arcuate edge surface 63,the edge 63 adapted to be positioned immediately below the meter needle45 when the module is at the readout position on the carousel. Themodule further includes a pair of spaced projections 64 on the uppersurface, and a depending cam pin 65 on the base plate. Also, the frontedge face of the module includes a pair of openings 66, 66' leading to apair of slots 67, 67' through the base plate 61.

As mentioned above, the module itself incorporates a portion of thecircuitry of the instrument. Referring to FIGS. 11 and 13, the moduleincludes a calibration adjustment including a variable resistor 70 inseries with a fixed resistor 71. The resistor 70 is manually adjustableby rotation of the screw 73 which is accessible through 74 in a serieswith a fixed resistor 75. The resistor 74 in- C i l 0 ll a r 1 (l lmeans 76. The leads from these two circuits are connected to theterminals 77 which extend through the base plate of the module.

As will be apparent from FIG. 1, each module is positioned on thecarousel by sliding it through the opening 26 in the upper cover 12. Asthis occurs, the clips 37 enter the module through the openings 66, 66'and lock into the slots 67, 67. Thus the module is firmly retained inits proper position on the carousel.

When the carousel is manually rotated 90 counterclockwise, the modulewhich has entered through opening 26 will arrive at the meter read-outstation 28. At this position, the resilient electrical contacts 40 inthe instrument pass through the opening 39 in the carousel to engage theterminals 77 of the module (see FIG. 8). Thus, the calibration andzero-set circuits of the module are connected to the circuit in theinstrument. Concurrently with the rotation of the carousel, the pin 65on the module engages the wheel 57 of the lever arm 34 (see FIG. 7) torotate the lever arm until the appropriate filter is in position in thephotometer. As will be apparent, the exact placement of the pin 65 inthe module base plate determines which filter will be positioned in thephotometer. By moving the pin closer to the center of the module, afilter closer to the lever arm will be selected.

The overall electrical system for the present invention is shownschematically in FIG. 2. It comprises the off-on switch 16 leading froma 110-volt, 60-cycle source to the power supply circuit 80. The powersupply circuit feeds the operational amplifier 81, the input of which iscontrolled by the cuvette actuated switch 53 and is connected to eithera thermometer 82 or the photocell 49. As a convenience feature, thethermometer 82 is attached to the 95 C. incubator block. When thethermometer is connected through the switch 53 and amplifier 81 to themeter 29, the meter reading will indicate the temperature of thermometer82 to thereby serve as a convenient check for the temperature of thisincubator. As noted above, the switch 53 is controlled by the entry ofthe cuvette into the test well, and thus switch-over to the temperaturecheck mode occurs automatically when the cuvette is removed from thewell 48. The meter 29 shifts back to determination reading from thephotocell 49 as soon as a cuvette is placed in the well.

The power supply circuit also services the voltage regulator 83 which isdesigned to prevent line fluctuations from varying the intensity of thelamp 47 and thereby degrading determination accuracy. In addition, thepower supply circuit feeds the thermostatically controlled heaters 84and 85 for the two incubators.

As previously mentioned, some of the elements of the circuit arepositioned in the removable modules which plug into the instrument. Inthis regard, the module contains a gain control calibration for theamplifier which serves to scale the meter for the particular test beingrun. The gain control calibration comprises the resistors 70 and 71which are connected across the terminals 77 into a feedback loop in theamplifier 81. Also included in the module is the zero set circuitcomprising resistors 74 and 75, this circuit establishing theoperational point of the voltage regulator and thus serving to controlthe intensity of light emanating from the lamp 47. Both the calibrationand zero set circuits in the module are easily adjusted by rotation ofthe screws 73 and. 76, respectively.

To complete the description of the circuitry shown in FIG. 2 the lightemanating from the lamp 47* passes through a filter 56 to the photocell49. As previously noted, the particular filter employed is automaticallyselected by the module for the test being conducted. The photocell 49,which serves as the amplifier input when the amplifier is calibrated forthe particular test being run by the gain control in the module, andthus the meter 29 indicates the test results in appropriate unitsdirectly on the module scale 62.

A further aspect of the present invention resides in the use of aremovable patient record element 90 as illustrated in FIGS. l415. Theelement 90 is fabricated from a sheet of paper-like material andincludes a data card 92 and two detachable tab portions 94. The datacard 92 correspounds in outer configuration to the upper face of themodule 27 and includes a scale 95 printed adjacent the arcuate upperedge. The card 92 is adapted to overlie and be retained on the upperface of the module 27, and a pair of apertures 96, which are designed toreceive the projections 64, are provided for this purpose. Whenpositioned in this manner, the reading of the meter may be markeddirectly on the scale 95 to make a permanent record of thedetermination.

It will be understood that each card 92 is printed with the name of thetest for which it is designed (e.g., hemoglobin) and that it is adaptedfor use only with the corresponding module. In this regard, the entireelement 90 may be color-coded to correspond with the color of theappropriate -module. Also, the spacing of the projections 64 on themodule and the aperture 96 on the card are correlated such that the cardfor a particular determination will fit only the corresponding module.

The tear-off tabs 94, which may also be color-coded, are connected tothe card 92 across the incised lines 97. These tabs are adapted to bemarked with the name or number of the patient for identificationpurposes, and are adapted to be attached to both the micropipettecontaining the blood sample and also the reagent cuvette. As will bemore fully explained below, a number of apertures 98 are positioned inthe tabs for this purpose.

It will be noted in FIG. 14 that the scale 95 (as well as scale 62 onthe module) includes a reading marked 95 C. As set forth above, themeter 29 will be operatively connected to the thermometer 82 when thecuvette is removed from the test well. Since the thermometer 82 isattached to the 95 C. incubator, this system provides an automatictemperature check of this incubator during intervals betweendeterminations. The 95 C. mark on the scale corresponds to the meterreading indicative of the proper temperature. It will be apparent that asimilar temperature check could be provided for the 37 C. incubator. Ifnot, the 37 C. incubator may be checked with a thermometer in a waterfilled vial which is placed in one of the openings 21. The scales 95 and62 also include a calibration setting (marked CAL) for the purposeshereinafter set forth.

There are several conventional methods in which to collect a bloodsample from the patient which are applicable for use in this system. Forexample, a finger puncture may be made and a capillary tube utilized tocollect a predetermined amount of whole blood which for most tests wouldnormally be about 72 microliters. Another way to obtain a blood samplewould be to make a venipunoture and collect a larger sample in anevacuated container or similar vessel by use of a syringe or similarmeans. In any event, whether the container be a test tube or a capillarytube it is thereafter centrifuged to separate the whole blood cells fromthe plasma or serum. It is well known that upon centrifugation, thewhole blood cells, will be packed into one end of the vessel and theremaining fluid which will be substantially blood plasma will collect inthe remaining portion of the container. There will generally be a clearpoint of demarcation between the blood cells and the plasma.

A micro-pipette is then employed, such as the micropipette 100illustrated in FIG. 17 to collect a predetermined volume of plasma orserum from the centrifuged sample. Micro-pipette 100 is accuratelydimensioned and thereby serves both as a precise measuring device(normally 30 microliters when filled) as well as a transfer vessel.

If a capillary tube 100a is utilized to collect the initial whole bloodsample and requires centrifugation, a cap 102 may be employed to closeone end of the capillary tube 100a for centrifugation purposes.

To maintain patient identification, one of the cabs 94 from the patientrecord element may be positioned on the capillary a by threading themicro-pipette through two of the apertures 98.

The patient record element 90 further includes a scale 103 useful inrecording the percentage of red blood cells in the sample (i.e.,Hematocrit). This procedure is applicable when the original sample iscellected from a finger puncture into capillary tube 100a, capped at oneend and then centrifuged. The heavier red cells will be positioned atone end of the capillary tube 100a as described above. Thereafter, bypositioning the capillary tube 100a in longitudinal alignment with thescale 103, a mark may be made on the scale at the interface between theplasma and packed red cells. This mark then serves as a record of theHematocrit. To permit accurate placement of the capillary 100a on thescale 103, a cut-out 104 may be provided to receive the cap 102.

The above described procedure is applicable for most tests to which thissystem is directed. However, there are several tests where thisprocedure would not be applicable. For example when performing ahemoglobin test which is performed by this system, a sample of wholeblood is transmitted directly to the cuvette. In the hemoglobin test,there is no necessity for an intermediate centrifugation step toseparate the plasma from the blood cells in order to transfer only theplasma to the cuvette. The hemoglobin test requires that the whole bloodsample be transmitted immediaely upon collection from the patient to thecuvette for testing. Therefore, a micro-pipette is employed to collectthe sample, normally 10 microliters when filled. This lO-microliterpipette is then transferred directly to cap 105 and into the cuvette fortesting. No centrifugation step is carried out and the whole bloodsample is subject to the hemoglobin test in the apparatus.

When tests other than the hemoglobin test are being carried out, and acapillary tube 100a is employed to collect the initial sample and isthereafter capped, centrifuged and the Hematocrit is read, the followingsteps are then carried out. The tube, which contains approximately 72microliters of centrifuged blood must then be broken so that the redcells can be discarded, and then by utilizing the 30-microlitermicro-pipette 100, 30 microliters of plasma is transferred from theremainder of the capillary tube 100a into the SO-microlitermicro-pipette. This is accomplished by direct contact between the twovolumetric containers.

To assist in the transfer of the measured blood sample in themicro-pipette into the reagent cuvette, a specially designed moldedplastic cap 105 is illustrated in FIGS. 16, 18-22 is provided. The capcomprises an outed cylindrical flange 106 having a female threadformation 107 on its internal surface which is adapted to engage 2.corresponding external thread formation on the open end of the cuvette25. An inner cylindrical plug 108 is positioned coaxially within thecylinder flange and is integrally joined thereto by a transverse basewall 109. The outer surface of the plug 108 is spaced from the innersurface of the flange 106 to form a cylindrical vial receiving openingtherbetween. By design, the outer diameter of the plug is slightlygreater than the internal bore diameter of the cuvette such that theplug provides a tight seal when the open end of the cuvette is threadedinto the cap. Also, the internal diameter of the flange 105 may bedimensionally controlled to sealingly engage the outer surface of thevial. In this manner, an inside-outside seal is provided.

Viewing FIGS. 20 and 21, it will be observed that the plug 108 of thecap is hollow for substantially its entire axial length. In any event,the forward end of the plug terminates in a resilient tubular section110 which may be slightly tapered to form a conical external surface forfacilitating entry of the plug into the cuvette.

An elongated flap 112 is integrally connected to the forward end of theplug 108. In the embodiment illustrated, the flap extends into andsubstantially bisects the tubular section 110. The remote end of theflap includes an aperture 113. As shown in FIG. 20, the micro-pipette isadapted to be threaded through the aperture 113 and into the tubularsection 110 of the plug. By this arrangement, the micro-pipette isconveniently retained in coaxial alignment beneath the cap;

The base wall 109 of the cap further includes a number of protuberances114 thereon. The number and spacing of the protuberances on the cap aredesigned to correspond with the apertures 98 in the tear-off tabs 94 ofthe patient record element 90. Thus as illustrated in FIG. 16, the capis adapted to mount one of the tabs 94 for identification purposes.

The cap 105 can obviously be fabricated from a wide variety of rubber orplastic materials. For purposes of example, polyethylene has been foundto be very satisfactory for this purpose.

The manner in which the patient record cards may be organized intomeaningful graphical displays to aid the physician is illustrated inFIGS. 23 and 24. Very often, trends and variations that show up over aperiod of time are more meaningful than any single blood componentdetermination. As blood sample tests are made at regular intervals, thepatient record cards for the component of interest are filled out andmarked. When arranged in overlapping sequence on the monitoring form117, they create a graph of the determinations plotted against time. Theprogression of determination marks may be scanned at a glance and itwill become easy to spot sharp variations or gradual trends. A clearplastic overlay 118 may be used in conjunction with the monitoring form117. This overlay, which matches the form, is marked at 119 to show thenormal range of the particular blood component for which it is designed.This feature enables the physician to work faster in that it gives himspeedy assurance as long as the determinations remain within the normalrange.

Often, the interrelationships of the various blood componentdeterminations will be indicative of the patients general physicalcondition. Presenting all of this information to the physician in asingle graphic display enables him to quicken the professional judgementthat he must exercise. For this purpose, a profile record form 120 asillustrated in FIG. 24 may be provided. This form is designed to be agraphic filing place for several patient record cards showing diiferentblood determinations made at one time.

In order to facilitate understanding of the present invention, theprocedure for obtaining a typical blood determination will be described.As an example, it will be assumed that it is desired to determine theamount of glucose in a particular blood sample. First, the instrument isturned on and a glucose module is positioned at the meter read-outstation. To calibrate the instrument, two known reagent samples arerequired. One of these samples is a zero-setting reagent blank, whilethe other sample is a standard which will yield light transmissioncharacteristics that match those of a known concentration of thecomponent of interest. When the blank reagent is placed in the testwell, the meter indication should be exactly zero. If it is not, it maybe corrected by rotating the zero adjustment screw 76 on the module.When the standard reagent sample is placed in the well, the meterindicator should fall on the preprinted calibration mark (CAL) on thescale. Similarly, this reading may be adjusted by rotating thecalibration screw 73 on the module. Once the module is calibrated,removing it from the instrument will not upset its calibration. However,since the chemistry of comercial reagents may vary slightly,recalibration is recommended Whenever a new supply of reagent isutilized.

For performing the glucose test, a reagent is required which will reactwith the glucose in the blood sample to form a color which may bemonitored by the colorimeter. For purposes of example, a suitableglucose reagent is an orthotoluidine in glacial acetic acid. Thisreagent reacts to form a blue-green color, the light transmissioncharacteristics of which will indicate the concentration of glucose. Ameasured amount of the glucose reagent is in the optically correctcuvette 25 having the cap 105. The reagent being employed for aparticular test generally is prefilled in the cuvette in a preciseamount. All the user is required to do is to utilize the cuvette whichhas been prepared for the glucose test. At this time, the glucosepatient record card is filled out with the patients name and number, andone of the tabs 94 is placed on the cap 105, utilizing the protuberances114 on the cap to engage the apertures 98.

A sample of blood is then obtained from the patient in a suitablecontainer such as a capillary tube a containing 72 microliters of wholeblood collected from a finger puncture. The capillary tube 100acontaining 72 microliters of whole blood is then centrifuged to separatethe red blood cells from the plasma or serum. If desired at this point,a Hematocrit reading may be taken. Thereafter, the capillary tube 100ais scored and broken in a common well known manner at a point just belowthe line of demarcation between the red blood cells and the plasma,preferably on the plasma side.

The 30-microliter micro-pipette 100 is then brought in contact with theplasma containing portion of the broken capillary tube 100a and ameasured plasma sample of 30 microliters is collected in micro-pipette100.

The micro-pipette 100 containing the measured plasma sample may beimmediately mounted on the cap by threading it through the aperture 113in the flap 112 and into the tubular section 110, note FIG. 21. In thisconfiguration, the micro-pipette is inserted into the cuvette with thecap closing and sealing the open end thereof, note FIG. 18. To rinse theplasma from the micropipette and to mix it with the reagent contained inthe cuvette, it is necessary to shake the cuvette up and downvigorously.

To expedite the reaction between the glucose and the reagent, thecuvette 25 is placed in the 95 C. incubator block for ten minutes. Thetimer 16 may be utilized to measure the time duration. After this timeperiod has elapsed, the cuvette should be removed from the incubator andplaced in a beaker of cool water for three or four minutes.

With the cuvette still tightly capped, it is wiped dry and placedthrough the guide 18 and into the test well 48 of the instrument. Thepatient record card 92 is then positioned on the glucose module whichhas previously been positioned at the meter read-out position. Theglucose determination is marked directly opposite the indicator meterneedle. Duplicate patient record cards may be completed at this time ifso desired.

From the preceding description, it will be apparent that the presentinvention provides a completely self-contained blood testing systemwhich is eminently suitable for achieving the above noted objects. Whilea specific embodiment of the invention has been described in detailherein, it should be understood that the legal scope of the invention isto be determined by the claims only.

What is claimed is:

1. In combination, a tubular vial having an open end, a micro-pipette,and a molded plastic cap adapted to close said open end of said vial andto retain said micropipette within said vial, said cap comprising,

an outer cylindrical flange having means thereon to releasably engagesaid vial open end,

an inner cylindrical resilient plug positioned coaxially within saidflange, one end of said plug being integrally joined to said flange by atransverse wall, the outer cylindrical surface of said plug being spacedfrom the inner surface of said flange a distance sufficient to receivesaid vial open end, and

a flap extending from the free end of said plug,

said flap having means to releasably retain said micropipette insubstantially coaxial relationship.

2. The combination as defined in claim 1 wherein said means toreleasably retain said micro-pipette includes an aperture through saidflap.

3. The combination as defined in claim 2 wherein said tubular vial hasexternal threads positioned on its open end, and said means on saidouter cylindrical flange to engage said vial open end comprise matingfemale threads.

4. The combination as defined in claim 3 wherein a plurality ofprotuberances extend from said transverse wall in a direction oppositesaid flange and plug.

5. The combination as defined in claim 4 wherein the opposite free endof said plug is substantially tubular, and said flap extends into andsubstantially bisects said tubular portion, the opening between saidflap and said plug end 12 of being of sufficient width to receive oneend of said micro-pipette.

6. The combination as defined in claim 5 wherein said plug has an outerdiameter slightly greater than the internal diameter of said vial openend whereby said plug acts to sealin-gly close said open end byresiliently engaging its internal wall.

References Cited UNITED STATES PATENTS 2,558,987 7/1951 Shaw 215-43 R2,582,721 1/1952 Roshkind 2l543 R 3,044,648 7/1962 Cohn 215-49 3,494,2012/1970 Roach 23-292 JOSEPH SCOVRONEK, Primary Examiner D. LOVERCHECK,Assistant Examiner US. Cl. X.R.

